Question

A ball of mass 5kg is released from a height of 45m above the ground, if the ball strikes the ground
then the work done by air resistance will be
-1500​

Answer 1

Answer:

-1250J

Step-by-step explanation:

v(sq) + u(sq) = 2as

400 = 2 a 45

a = 40/9 ; this is resultant of g and acceleration due to air resistance

lets assume acceleration due to air resistance as x

so,

g - x = a

x = 10 - 40/9 = 50/9

now force due to air resistance will be ma

= 5 * 50/9

w = f.s

= 5*50/9*45 = 25 *50 = 1250 J

but force is in opposite direction of displacement so -1250J